1. Field of the Invention
This invention relates to a fitting for coupling two tubular members, more particularly to a position-recoverable pulling device adapted for use in a fitting that couples two tubular members.
2. Description of the Related Art
Referring to FIG. 1, a conventional fitting for coupling two tubular members (not shown) is shown to have an annular coupling body 10 with a locking bore 101 which extends downwardly, and a pressing lever 12 with a pivoted end portion 121 which is pivotally mounted on the coupling body 10, an actuating end portion 123 which is turnable between locked and unlocked positions where the actuating end portion 123 is closer to and remote from the coupling body 10, respectively, and a lock body 124 with a chamber 122 and a spring-loaded lock bolt 13 which is received in the chamber 122 and which is movable relative to the lock body 124 longitudinally. The lock body 124 has an upper locking end 131 which extends upwardly and outwardly of the lock body 124 and which is urged to move into and to be retained within the locking bore 101, and a lower pulled end which extends downwardly and outwardly of the lock body 124 and which is provided with an anchoring member 133 with an anchoring hole 132 for engaging a coiled pulling member 15. By pulling the coiled pulling member 15, the lock bolt 13 is pulled downward to detach the upper locking end 131 from the locking bore 101 so as to permit turning of the actuating end portion 123 of the pressing lever 12 to the unlocked position.
Since the coiled pulling member 15 is hung on the anchoring member 133, when the fitting is mounted on two tubular members which are in an inclined state, the coiled pulling member 15 will incline and is not in line with the lock bolt 13 due to its weight. Thus, it is required to adjust the position of the coiled pulling member 15 to register with the lock bolt 13 for pulling when unlocking the pressing lever 12, thereby resulting in inconvenient operation thereof.
The object of the present invention is to provide a position-recoverable pulling device which is adapted for use in a fitting and which is position-recoverable to be in line with a lock bolt of the fitting when the fitting is inclined.
According to this invention, the position-recoverable pulling device includes an anchoring member and a coiled pulling member. The anchoring member includes front and rear walls opposite to each other in a first transverse direction. The front wall has an anchoring hole which extends in the first transverse direction to communicate with the rear wall and which defines a hole axis. Upper and lower end walls are disposed opposite to each other in a longitudinal direction at opposite sides of a middle line that is aligned with a chord line of the anchoring hole which is transverse to both the hole axis and the longitudinal direction. The upper end wall is adapted to be attached to a lower pulled end of a spring-loaded lock bolt of a fitting such that the hole axis crosses a bore axis of a coupling body of the fitting. Right and left lateral walls are disposed opposite to each other in a second transverse direction which is transverse to both the longitudinal direction and the first transverse direction. At least one of the right and left lateral walls has a cam surface which includes a normal spot that is distal to both of the upper and lower end walls, and that is the closest to the hole axis in terms of radial direction, and a swung spot that is proximate to one of the upper and lower end walls and that is farther from the hole axis than the normal spot in terms of the radial direction. The coiled pulling member is made of a resilient material, and includes a plurality of loops defining a loop axis. The adjacent ones of the loops are biased to abut against each other in a direction parallel to the loop axis. The coiled pulling member includes a leading end and a tail end, and is brought to be hooked on the anchoring member by inserting at least one of loops into the anchoring member with a cross sectioned area thereof disposed within the anchoring hole, while one of the leading and tail ends is pulled in the parallel direction away from an adjacent one of the loops against biasing action of the pulling member such that an outer segment proximate to one of the leading and tail ends is disposed outboard to a respective one of the right and left lateral walls. The outer segment has a bent portion which is localized at and slidably contacted by the normal spot in a normal position of the coiled pulling member where the loop axis is parallel to the middle line, and which is bent away from the adjacent one of the loops in the parallel direction so as to relieve the biasing action in the parallel direction to render the bent portion to act as a follower that follows the contour of the cam surface. Once the coiled pulling member has been swung to move the bent portion to reach the swung spot against the biasing action, the bent portion will be brought to slide back to the normal spot, thereby bringing the coiled pulling member to move back to the normal position.